What is a GURPS Turn?

Like most RPGs GURPS uses Combat Turns to divide up combat into
distinct actions for each character (PC or NPC). However, GURPS turns are a little different than what some other RPGs consider at
"turn." For starters GURPS doesn't use a universal "Round" of
turns,
instead using a simple round-robin style turn ordering where every PC and NPC
takes a turn in sequence. When you get to the end of the sequence you simply
continue on from the beginning again, and that sequence doesn't change during combat. GURPS
Turns are also relatively short compared to many other RPGs, but once you get to
know the game this won't be an issue.

In the simplest example of two players this means that the turn sequence will
simply be:

Player A Turn 1

Player B Turn 1

Player A Turn 2

Player B Turn 2

Player A Turn 3

Player B Turn 3

etc.

After every time Player A takes a turn Player B will take a turn, and after
every time Player B takes a turn then Player A takes a turn. In the end this is
the fairest way of handling things, as it means that at no point will A get to
take two turns in a row without consequences, something that often times happens
where players roll for initiative at every round.

Doesn't GURPS use Initiative?

Yes, it does, but what GURPS calls "initiative" is not what other games
generally call "initiative." Other games generally use initiative as a process to
order or reorder the turn sequence every so often, usually at the beginning of
combat and again every combat round. You
"roll for initiative" at the beginning of every round, with the player
who rolls the best getting to act first in the turn sequence.

In GURPS initiative is used when one group of characters (PCs or NPCs)
surprises another group at the beginning of combat, or when two groups stumble
upon and surprise each other. The side that gains initiative is not surprised
and may act normally while the side that loses initiative is confused and may be
mentally "paralyzed" for several seconds while they get their
bearings. It is possible for both sides to win initiative and thus act normally
or, in the case of two groups surprising each other, for both sides to lose.
Some traits, particularly the advantage Combat Reflexes, help prevent individual
characters from "freezing up" so that they can react decisively. See Surprise
Attacks and Initiative on p. 393 of GURPS Basic Set: Campaigns for a
full description of initiative in GURPS.

How to Determine Turn Sequence

In GURPS Turn Sequence - the order in which characters take their turns
- is determined solely using a character's Basic Speed sub-attribute; the character
with the highest Basic Speed goes first in the sequence, followed by the next
highest Basic Speed, and so on. In the case of a tie the character with the
highest DX goes first; if there is still a tie a die roll or other method can be
used by the GM to determine who goes first. Once the Turn Sequence is set it
does not change throughout combat; it's important to note that Turn Sequence is
notrandomly
generated except in the case of breaking ties.

A house rule that is sometimes used is to just go round-robin around the game
table, with the player to the GMs left going first and proceeding around the
table with each player taking their character's turn in sequence, possibly with
some NPC turns coming after each player's turn (usually
the NPC that is facing off against that player or that is facing off against the
next player in sequence). Since this means that Turn Sequence doesn't change during
combat it maintains the combat rules structure and can serve as a simplification
of combat, making it easier for the GM and players to know who's turn it is (especially for
new players).

Some GMs like to use a house rule to randomly set Turn Sequence, for
example by adding 1d6 to Basic Speed to determine Turn Sequence. While doing
this doesn't necessarily break the game, this should only be done once
at the beginning of combat; once combat has started the Turn Sequence should not
change. Having a randomly generated Turn Sequence every "round"
will breaks several fundamental aspects of the combat rules and can
unexpectedly unbalance the game. Players who discover where these breaks are and
how to exploit them will usually do so, much to the frustration of the GM. Thus,
it is best to just not go down that path, even if you are used to having turn
sequence be re-determined during combat in other games. Also, an experienced GM
will find it convenient to have a predetermined Turn Sequence he can reference
instead of having to write down a new one every combat and especially every
combat "round."

Turn Length

As I said before, each character's turn lasts one second. While this may seem
short, it is enough time to do quite a bit in GURPS combat. It's enough
time for an average character to run 4-6 yards, which will cross an average
sized room in one to two seconds. It's enough time to swing a sword or fire a
gun several times. While some people new to GURPS feel an urge to
increase the turn length doing so will fundamentally alter the way several of
the combat rules interact so I recommend against doing so and to just play with the rules as
they're written.

Each character's turn begins when the "timer" for their 1
second of action begins; that 1 second lasts throughout all the other players
taking their turn and finally comes to an end just before the beginning of their
next turn. This means that each character's turn starts and stops at
a different moment in time from each other character's turn. If you observe the turn
sequence table below you can see how these turns overlap, with Player A's first
turn starting things off, then Player B's first turn starts, then player C's
first turn starts. Only after Player C's first turn has started and he's
declared and taken his actions does he "pass turn" back to Player A
who's first turn comes to and end so he can start his second turn. However,
Player B & C's first turns continue on into Player A's second turn.

A1

A2

A3

A4

A5

B1

B2

B3

B4

B5

C1

C2

C3

C4

C5

GURPS turns can be thought of as being informally
divided into an Active Phase and a Reactive Phase. When
a player starts his turn he begins in the Active Phase. The first thing he does
is declare his actions for his turn and then the rules and the GM will instruct
him on how to resolve his actions. For instance, if at the start of Player A's
second turn he decides his action will be "I attack Player B with my
broadsword" the GM will instruct him to roll against his Broadsword skill.
If he succeeds Player B will get a chance to defend, if Player B fails to defend
Player A will roll damage, and the results of the damage roll will be fully
resolved. With nothing else he can do Player A will then "pass turn"
to player B and Player B's second turn will begin.

However, Player A's second turn does not end there, instead he has entered
the Reactive Phase of his turn. During this phase he cannot take any
actions, but may react to things that happen to him. If he's attacked he can
defend; if a drug cloud enters his hex or he is drugged or if a spell is cast on him he may be able to resist it. This reactive
phase lasts until the beginning of his next turn, so it will last through the Active Phase
of all of the other characters (PC and NPC alike). Thus, what
actions you take during your Active Phase will affect what defenses
you are allowed to use during the Reactive Phase as all other players take
their actions.

In the table below I've divided each players turn into the Active Phase
(labeled with a -a and in a darker red or blue) and Reactive Phase
(labeled -r and in a lighter pink or aqua blue). As you can see while a
players Reactive Phase overlaps other players Active Phases, each
player's Active Phase does not overlap any other player's Active Phase.
When it is your turn to act it is your turn and other players don't get to act
(with the exception being when another character takes the Wait
maneuver, which allows them to interrupt the Active Phase of another
players turn; see Basic Set: Campaigns p. 366 for a description of how Wait
works).

A1-a

A1-r

A2-a

A2-r

A3-a

A3-r

A4-a

A4-r

A5-a

A5-r

B1-a

B1-r

B2-a

B2-r

B3-a

B3-r

B4-a

B4-r

B5-a

B5-r

C1-a

C1-r

C2-a

C2-r

C3-a

C3-r

C4-a

C4-r

C5-a

C5-r

Generally, anything that your character is actively doing will be completely
resolved during the Active Phase of his turn, unless he takes a Wait
maneuver or the action is a
multi-turn action (e.g. casting many spells takes more than one second of
concentration). In those cases on the turn the character takes the final
maneuver to complete the multi-turn action that action will be resolved during that turn's Active
Phase. I.e. if Player B starts casting a three second round on turn B1
he will declare his maneuver as a Concentrate on B1-a, then declare Concentrate
on turn B2-a. On turn B3-a he declares his third Concentrate maneuver, and
during B3-a he completes his three turn of concentration and may cast the spell,
rolling skill to see if it takes effect and resolving any other effects it has.
If Player C decides to cast a one second spell on his second turn he declares
his maneuver as Concentrate on C2-a; since the spell takes only one second this
means he may immediately cast the spell, roll for success, and determine its
effects.

Again, generally when a rule says "an effect lasts until the end of your turn" it's
talking about the very end of your turn, the end of the Reactive Phase and just before your next turn begins.
Some effects will last "until the end of your next turn," in which
case they will take effect during your current Reactive Phase, last
through the Active Phase of your next turn, and then continue to linger
through that turn's Reactive Phase, only ending when that Reactive
Phase is over and you begin the following turn. I.e. suppose that Player C
successfully cast that spell on his turn C2-a, affecting Player A who is
currently in the Reactive Phase of his second turn, A2-a. The spell
effect says it lasts "until the end of the target's next turn;" So the
spell takes effect immediately and Player C's Active Phase ends, so he
ends "passes turn" to Player A. Player A starts his third turn, with
the spell in full effect. He declares his action and passes turn to Player B.
Player B was casting a spell which he rolls for during his Active Phase
B3-aand resolves its effects. Then Player C gets to take his third turn;
once he ends the Active Phase of his third turn and "passes turn" to
Player A this marks the end of Player A's third turn, the spell that was
affecting him ends, and he begins his fourth turn's Active Phase.

Adding more characters to the turn sequence simply expands the diagram out a
bit, as shown in the table below.

A1-a

A1-r

A2-a

A2-r

A3-a

A3-r

A4-a

A4-r

A5-a

A5-r

A6-a

A6-r

A7-a

A7-r

A8-a

A8-r

A9-a

A9-r

A10-a

A10-r

etc->

B1-a

B1-r

B2-a

B2-r

B3-a

B3-r

B4-a

B4-r

B5-a

B5-r

B6-a

B6-r

B7-a

B7-r

B8-a

B8-r

B9-a

B9-r

B10-a

B10-r

etc->

C1-a

C1-r

C2-a

C2-r

C3-a

C3-r

C4-a

C4-r

C5-a

C5-r

C6-a

C6-r

C7-a

C7-r

C8-a

C8-r

C9-a

C9-r

C10-a

C10-r

etc->

D1-a

D1-r

D2-a

D2-r

D3-a

D3-r

D4-a

D4-r

D5-a

D5-r

D6-a

D6-r

D7-a

D7-r

D8-a

D8-r

D9-a

D9-r

D10-a

D10-r

etc->

E1-a

E1-r

E2-a

E2-r

E3-a

E3-r

E4-a

E4-r

E5-a

E5-r

E6-a

E6-r

E7-a

E7-r

E8-a

E8-r

E9-a

E9-r

E10-a

E10-r

etc->

F1-a

F1-r

F2-a

F2-r

F3-a

F3-r

F4-a

F4-r

F5-a

F5-r

F6-a

F6-r

F7-a

F7-r

F8-a

F8-r

F9-a

F9-r

F10-a

F10-r

etc->

It's important to note that the rules as written don't formally describe
turns as having an Active Phase and Reactive Phase,
however the way that the rules are written do support this description
and interpretation. Breaking it down into phases is just a convenient way for
me to describe it to help you understand it.